Yes, in many ways lemm.ee shutting down is a great example of the intention of a federated network at work, but it is also somewhat of a cautionary tale when it comes to centralisation. Ideally the load would be spread as such that any single instance shutting down would be reasonably painless to adjust for. There were already too many users and communities on .ee, really. Imagine what a disaster .world shutting down would be in the current state of things.